The presently disclosed subject matter relates to a biological information measuring apparatus and a biological information measuring method for a non-invasive blood pressure measurement.
An intra-aortic balloon pumping (IABP) is a circulation assisting apparatus which is widely used for a left ventricle. In an IABP, a balloon catheter is placed in the thoracic descending aorta of a subject, and the balloon is inflated and deflated in synchronization with the pulsation of the heart to pressure-assist the heart to increase oxygen supply to the cardiac muscle and to reduce oxygen consumption by the cardiac muscle.
For example, JP2007-503883A discloses an apparatus having a function of optimally setting the treatment timing of an IABP.
A blood pressure value is an important vital sign for understanding the condition of the subject. Therefore, it is preferable, also during use of an IABP, to correctly know the blood pressure value of the subject. Hereinafter, the non-invasive blood pressure (NIBP) measurement will be discussed.
In the non-invasive blood pressure measurement, a cuff (manchette) is wrapped around the upper arm or the like of the subject, and the upper arm and also the artery passing inside the upper arm are compressed by the air sent into the cuff. The pulsation of the compressed artery is transmitted as vibrations to the cuff (oscillation), and the blood pressure value is calculated from the degree of the vibrations. In a case where the subject uses an IABP, however, a blood pressure value calculated based on the balloon-assisted heartbeat (e.g., a systolic pressure (SYS), a diastolic pressure (DIA) and a mean arterial pressure (MAP)) and a blood pressure value calculated based on the unassisted heartbeat of the subject (e.g., a systolic pressure (SYS), a diastolic pressure (DIA) and a mean arterial pressure (MAP)) cannot be distinguished from one another. Accordingly, the blood pressure values cannot be obtained accurately.